Providing better thermal and air quality conditions in school classrooms would be cost-effective

Energy retrofits have the potential to reduce building energy consumption and carbon emissions, but face particular challenges when implemented in historic and traditionally constructed buildings. Retrofitting these buildings is a complex balancing act, in which many criteria are balanced against one another in order to achieve continued, long-term use of the building. This article reviews the criteria, analysis methods, and decision-making processes used to assess energy retrofits in historic and traditional buildings. First, the criteria are discussed. While energy consumption and conservation are the dominant criteria, a number of others are also important, including the needs of the building fabric, occupants, and collections, as well as economics, embodied energy, and climate change. Second, several analysis methods for estimating or measuring retrofit performance have emerged as particularly useful for historic and traditional buildings, and these are examined. Third, recent efforts to develop consistent guidance and decision-making processes for selecting retrofits are reviewed. Overall, energy retrofits in these buildings are seen not only as a way to reduce energy consumption, but as a means of preserving them for future generations.

Energy retrofits in historic and traditional buildings: A review of problems and methods

Methods for air cleaning and protection of building occupants from airborne pathogens.

Turbulent organized structures (TOS) above building arrays were investigated using a large-eddy simulation (LES) model for a city (LES-CITY). Square and staggered building arrays produced contrasting behaviour in terms of turbulence that roughly corresponded to the conventional classification of ‘D-type’ and ‘K-type’ roughness, respectively: (1) The drag coefficients (referred to the building height) for staggered arrays were sensitive to building area density, but those for square arrays were not. (2) The relative contributions of ejections to sweeps (S2/S4) at the building height for square arrays were sensitive to building area density and nearly equalled or exceeded 1.0 (ejection dominant), but those for staggered arrays were insensitive to building area density and were mostly below 1.0 (sweep dominant). (3) Streaky patterns of longitudinal low speed regions (i.e., low speed streaks) existed in all flows regardless of array type. Height variations of the buildings in the square array drastically increased the drag coefficient and modified the turbulent flow structures. The mechanism of D-type and K-type urban-like roughness flows and the difference from vegetation flows are discussed. Although urban-like roughness flows exhibited mixed properties of mixing layers and flat-wall boundary layers as far as S2/S4 was concerned, the turbulent organized structures of urban-like roughness flows resembled those of flat-wall boundary layers.

Large eddy simulations on the effects of surface geometry of building arrays on turbulent organized structures

a b s t r a c t Poor indoor environmental quality (IEQ) in classrooms may be a risk for health symptoms and cause absence from school. We conducted a comprehensive study in order to assess the connection between IEQ in Finnish elementary school buildings and the health and academic performance of sixth grade students. The specific aim of the present paper was to study the school- or grade-level prevalence of symptoms in relation to IEQ. The school- or grade-level (i.e. group level) prevalence of self-reported symptoms and perceived IEQ was studied using data collected by a health questionnaire comprising 37 questions. The health questionnaire was sent to all 6th grade students in a stratified random sample of 355 elementary schools in Finland. Indoor environmental conditions were assessed with measurements of ventilation rate and thermal conditions of classrooms in a subsample of 56 schools. Altogether 297 elementary schools participated in the health questionnaire study and a total of 4248 questionnaires were returned (estimated response rate 62.6%). The most common weekly symptoms in the spring semester were fatigue (7.7%), stuffy nose (7.3%), and headache (5.5%). However, both mean prevalence values for different symptoms among all 6th grade students and group-level prevalence values for specific symptoms varied considerably. On the group level, the prevalence values most frequently found above 95% CI (calculated for N = 15) were wheezing, cough with wheezing, and fever over 37 ◦

Indoor environmental quality in school buildings, and the health and wellbeing of students

Integrated impacts of tree planting and street aspect ratios on CO dispersion and personal exposure in full-scale street canyons

Numerical investigations of Re-independence and influence of wall heating on flow characteristics and ventilation in full-scale 2D street canyons

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Magnus Mattsson

Papers

Integrated impacts of tree planting and street aspect ratios on CO dispersion and personal exposure in full-scale street canyons

Numerical investigations of Re-independence and influence of wall heating on flow characteristics and ventilation in full-scale 2D street canyons

Displacement Ventilation: effects of movement and exhalation

Evaluation of the LBL and AIM-2 air infiltration models on large single zones: Three historical churches

Single-sided ventilation through external doors: Measurements and model evaluation in five historical churches